Password manager
Emergency access or recovery kit for the vault; some managers support delayed release to a nominated contact
Some steps differ by region inside the country.
Where
The password manager provider, using their emergency access or legacy feature. Check their browser saved passwords as well.
How
Look for a printed recovery kit or emergency sheet, most managers encourage users to keep one, often in a safe or with the will.
Check whether you were named as an emergency contact, which usually grants access after a waiting period.
If not, apply to the provider with the death certificate and grant, though genuinely zero knowledge providers may be unable to help at all.
Check the browser's saved passwords on their computer as a fallback, this often works when the vault does not.
What to bring
A certified copy of the death certificate
The grant of probate
Any recovery kit or emergency sheet they printed
This is practical information, not legal, medical, or financial advice.